A wide variety of minimally invasive surgical procedures have been developed which employ catheters, endoscopes, or other similar devices that can be navigated remotely from their distal ends. The catheter, endoscope or other medical device is manipulated through the tissue or through an existing body lumen or cavity using a guide wire or other mechanical means. Examples of such procedures include the treatment of aneurysms, arterial ventricular malformations, atrial fibrillation, ureteral stones, and investigations of lumen such as sigmoidoscopies and colonoscopies, ERCP's; and biliary duct examinations. While these procedures are highly beneficial to the patient, they are difficult and time consuming for the physician. Some procedures can only be performed by the most skilled surgeons.
Because of the small size of the vessels to be navigated, extremely high resolution and flexibly moveable fluoroscopes are needed to provide adequate imaging. These fluoroscopes are large instruments. Even now, accessibility of adequate imaging in the presence of equipment needed to navigate the catheters, endoscopes, or other similar devices through the vessels.
Systems have been disclosed for magnetic guidance of catheters and guidewires to facilitate navigation of difficult vascular turns. Imaging means can be used in conjunction with magnetically guided surgery. An example of such a system is described in U.S. utility patent application Ser. No. 09/020,798, filed Feb. 9, 1998, entitled “Device and Method for Specifying Magnetic Field for Surgical Applications,” now U.S. Pat. No. 6,014,580. While magnetically guided surgery with such systems is practical, the sheer bulk and size of their magnetic systems results in less accessibility of the operating region of the patient than a surgeon might prefer. Also, imaging equipment (such as X-ray equipment) for observing the operating region has been fixed to the magnetic system assembly, or otherwise been immobile or of limited mobility relative to the magnets and/or the patient. This relative immobility tends to reduce the ability of the surgeons to see the medical operating device within the patient, making the operation somewhat more difficult for the surgeon and somewhat riskier for the patient than might otherwise be the case. It would therefore be desirable to provide an apparatus for magnetically-assisted surgery that provides flexibility of both the imaging and of the magnetic field application.
A difficulty associated with magnetic guidance is that the magnetic field source needed to guide the medical devices within small vessels and body lumens may be relatively large. The distance between the magnet field source and the operating region is also a factor in providing a system for applying magnetic fields for navigation, while maintaining an “openness” and accessibility of imaging systems as described above.